Simulators reduce the financial cost of training and increase safety. The more realistic a simulation is, the better the training provided by the simulator will be. Further, a more realistic simulation makes it more likely that a trainee will learn and, when operating the actual vehicle being simulated, react appropriately.
A simulated cockpit used in a simulation may require substantial electronics to provide the visible and tactile feedback necessary to accurately simulate an actual cockpit. The electronics can be expensive, may require specialized cooling requirements, and need to be maintained and repaired over time.
Additionally, simulators often require one or more projectors that project simulated out-the-window imagery onto a screen, such as a domed screen, for a trainee. Such simulators are large, expensive, and costly to maintain.